Núcleo de Biotecnologia, Centro de Desenvolvimento Tecnológico, Universidade Federal de Pelotas, Pelotas, RS, Brazil.
Braz J Microbiol. 2013 May 14;44(1):165-70. doi: 10.1590/S1517-83822013005000029. eCollection 2013.
Pathogenic Leptospira spp. are the etiological agents of leptospirosis, an important disease of both humans and animals. In urban settings, L. interrogans serovars are the predominant cause of disease in humans. The purpose of this study was to characterize a novel Leptospira isolate recovered from an abandoned swimming pool. Molecular characterization through sequencing of the rpoB gene revealed 100% identity with L. interrogans and variable-number tandem-repeat (VNTR) analysis resulted in a banding pattern identical to L. interrogans serogroup Icterohaemorrhagiae, serovar Copenhageni or Icterohaemorrhagiae. The virulence of the strain was determined in a hamster model of lethal leptospirosis. The lethal dose 50% (LD50) was calculated to be two leptospires in female hamsters and a histopathological examination of infected animals found typical lesions associated with severe leptospirosis, including renal epithelium degeneration, hepatic karyomegaly, liver-plate disarray and lymphocyte infiltration. This highly virulent strain is now available for use in further studies, especially evaluation of vaccine candidates.
致病性钩端螺旋体是钩端螺旋体病的病原体，这种疾病对人和动物都有重要影响。在城市环境中，问号钩端螺旋体血清型是导致人类疾病的主要原因。本研究旨在对从废弃游泳池中分离出的新型钩端螺旋体进行鉴定。通过 rpoB 基因测序进行的分子特征分析显示与问号钩端螺旋体的同一性为 100%，可变数量串联重复（VNTR）分析导致与伊氏科坡尼亚群血清型或伊氏出血热群血清型相同的带型。在仓鼠致死性钩端螺旋体病模型中测定了该菌株的毒力。雌性仓鼠的半数致死剂量（LD50）计算为两个钩端螺旋体，对感染动物的组织病理学检查发现了与严重钩端螺旋体病相关的典型病变，包括肾上皮细胞变性、肝巨细胞、肝板排列紊乱和淋巴细胞浸润。这种高毒力的菌株现已可用于进一步的研究，特别是用于评估候选疫苗。
